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Lesson #25 -
Taking Apart A Computer
This week's lesson is
about the proper methods of disassembling computers.
Although it might seem simplistic, there is some very
important knowledge that you MUST know for the exams contained
within this lesson. Because more and more people are
trying to make their computers last longer and longer, being
able to upgrade a system is an important skill you must
have.
Don't Be
Shocked
The most important
piece of information you need for this section of the A+ exam
is a thorough understanding of Electro Static Discharge, or
ESD. ESD occurs when an electrical charge passes from
your body to an electrical component, which damages the
component and sometimes damages you. Humans can feel
this static passing through their body at about 3,000
volts. An IC begins degrading and failing at around 30
volts. Therefore, you won't even feel yourself damaging
your computer until it's too late.
The easiest methods
of avoiding ESD should be fairly routine for you now.
Use an ESD wrist strap, and place anti-static mats under
working areas. You should leave AT computers plugged
into the wall while working on them, but ATX cases continue to
run current through the motherboard even when turned
off. Therefore, remember that you leave AT alone and you
unplug ATX.
I remember the first
time I blew up a case. It was a wonderful sight.
The sparks that flew made a wonderful pattern in the now-dark
room, seeing as I popped every circuit on that side of the
house. The most interesting part was the burning hair
smell that I faintly noticed. Apparently the power
supply arced some current through my hand and burn off all the
hair on part of my hand and arm. Moral of the story :
Don't mess around with electricity, as much as you may love
the smell of burning hair.
More Electrical
Knowledge
Another safety issue
you should be aware of is the use of anti-static bags.
Most people think that anti-static bags are an insulator that
protects components from static. This is exactly
wrong. Anti-static bags are a conductor that protects
components from static. They shield components by
absorbing the static charges instead of passing them on to the
component.
What does this
matter? Well, let's say you just bought a $500 GeForce 3
video card and want to install it. You place the
anti-static bag on the chassis of the case and place the video
card on top of it. You go to pick up the video card and
feel a small charge run through your body, even though you're
grounded. What happened?
The chassis on a
computer is a ground. With the computer still plugged in
(Assuming an AT case or not having read the above section yet)
you created a path for a static charge from your body through
the video card through the anti-static bag to the grounded
chassis. This is why anti-static bags must be used with
better care than most of us usually do.
Even More Fun With
Electricity
Tired of the warnings
yet? Well, I have one more that you WILL see on the
exam. About 20 lessons ago I warned you that opening a
computer monitor was a bad thing. I will repeat that to
you now. OPENING A COMPUTER MONITOR IS A BAD
THING! There are capacitors that hold enough power to
curl even hair on your body, and maybe even stop your heart
while you're at it. The fly-back transformer holds
enough power to throw you a couple feet if you touch it.
Simply put, there's nothing in a computer monitor that you
would be expected to fix without a certification in
electronics. The A+ certification is not an electronics
certification, and therefore doesn't deal with
this.
If you do feel brave
and want to try opening a monitor, toss away your ESD wrist
strap first. Remember how you want to stop charges from
going to a computer by having them go through the strap to the
ground instead? With a monitor's large power sources,
the path you create with an ESD wrist strap allows all the
power in the monitor to pass through your body. In other
words, wearing an ESD wrist strap while working on a monitor
can kill you. (That's the answer to the question on the
exam.)
Before You
Start
The first thing you
should do before you start ripping the guts out of your
computer is the first thing you should do every time you work
on a computer system; Back-up the hard drive. If you
mess up the hard drive you'll need this backup to avoid
looking like an imbecile. Believe me, there's nothing
worse than sitting in front of a computer you just blew up and
having to look your client in the eye and tell them what you
did. Back-up the system and you're less likely to have
to make that apology.
Secondly, make sure
you have all the tools you will need in your possession.
This includes screwdrivers, thermal grease, your multimeter,
compressed air, rubbing alcohol, q-tips, pliers,
cutters......... Bring your whole toolbox every
time.
Lastly, write
everything down. Network cable positions, CMOS and BIOS
settings, IRQ's, driver names, modem types, card placements,
cable positions.... The more you write down, the less
you have to try to pull out of a hat (Or the gray matter
upstairs) later on when you run into a problem.
Lesson #1 -
Opening the Case
Okay, so you want to
disassemble the computer. Pop open the case
and.... Wait... what's that little sticker
on the back. "Void if Broken" What does that
mean?
If you see this
sticker, stop. This means the manufacturer has sealed
the unit, and breaking that little sticker can void the
warranty. Not all manufacturers do this, and in some
cases they'll even have you open the case yourself. The
key to this is to check first, and if you see a sticker call
the manufacturer before you attempt anything.
Okay, so we're beyond
the sticker situation. What next? First,
disconnect all the cables from the back of the computer.
If it isn't obvious, make sure you mark where each connection
is supposed to go. It will come in very handy when you
have to reattach the cables later on.
Secondly, examine the
case to find the screws that hold it all together. You
should only need to take off the top of a desktop case, or the
sides of a tower case. 99% of the cases use Phillips
screws, so one screw driver should be adequate. Remove
just enough screws to get the sections of case off that are
required. If you remove more screws, it's more chances
for you to lose a screw and screw (pardon the pun) something
up.
If you don't see any
screws, you've probably come across one of those old evil
screwless cases. Although my first instinct would be to
run, generally there is a simple method of disassembling these
types of cases. You just have to figure it out.
<snicker> It's easy. <snort>
They were designed to be easy to use.
<snicker> |